Overpressure security vent and exhaust device for a container

Abstract

A vent and exhaust device for a container within which an overpressure of gas can be created during use, such as a battery for a vehicle. The device having a hollow body, suited to being arranged on an opening of such container with internal cavity, closed but communicating with the outside and with a passage connected to the inside of the container from which the gas that forms in the latter can pass to escape to the outside of the aforesaid body. There being placed on such passage a filter element permeable to such gas. Such filter element is subject to pressure placed in such cavity and suited to pushing it in the position of interception of the passage, but allowing the momentary opening of the latter for a venting of the gas when the pressure exceeds a predetermined value.

The invention claimed is: 
     
       1. A vent and exhaust device for a container within which an overpressure of gas can be created during use, said device comprising:
 a hollow body suited to be arranged on an opening of such container, 
 the hollow body comprising a first portion defining an internal cavity and a second portion defining a passage, the internal cavity of the hollow body being closed, but communicating with the outside of the hollow body and the passage for connecting to the inside of the container, from the passage the gas that forms in the container is passable through the internal cavity to vent to the outside of the hollow body, 
 a ring-shaped support unit having a central hole, 
 a filter element integral with the ring-shaped support unit, the filter element placed within the central hole such that gas passing through a central opening to the internal cavity must pass through the filter element, 
 on the passage being placed the filter element permeable to such gas at a pressure of from 80 to less than 100 bars, 
 the ring-shaped support unit being subject to a biasing force exerted by a pressure element placed in the internal cavity of the body, the pressure element acting directly on the ring-shaped support unit, the force being suited and biased to push the support-unit and the filter element in a first position of interception or closure of the passage, 
 wherein the ring-shaped support unit is moveable from the first position of interception or closure of the passage to a second position raised away from the passage to open the passage to flow the gas around the ring-shaped support unit and into the internal cavity, 
 the pressure element allowing the opening of said passage for a venting of the gas when the pressure exceeds a predetermined value of 100 bar, but bringing such filter element back in the first position of interception when the pressure of the gas in the container returns below said predetermined value. 
 
     
     
       2. The vent and exhaust device according to  claim 1 , wherein the pressure element comprises a spring placed in the internal cavity of the body for directly exerting on the support unit a downward force for pushing the support unit and the filter element in the position of interception or closure of the passage. 
     
     
       3. The vent and exhaust device according to  claim 1 , comprising arms for protecting the filter element from overpressure coming from the inside of the container, such arms arranged radially within the central hole of the support unit. 
     
     
       4. The vent and exhaust device according to  claim 1 , wherein the filter element has internal stiffening units. 
     
     
       5. The vent and exhaust device according to  claim 1 , wherein the pressure element has extremities, and wherein the pressure element acts, with one of the extremities, opposite to another of the extremities acting on the filter element, on a closing element of the internal cavity of the body of the device. 
     
     
       6. The vent and exhaust device according to  claim 5 , wherein said closing element is alternatively fixed to the body or is bound to the body in a removable way through mechanical coupling, at least one of said closing element and said body of the device defining at least a passage connecting the internal cavity of the hollow body with the external environment, such passage for passing the gas coming from the container. 
     
     
       7. The vent and exhaust device according to  claim 1 , wherein said body comprises a first portion connected to a second portion,
 the first portion having the cavity containing the pressure element and being closed at an extremity of the closing element, 
 the second portion having the passage for communicating with the inside of the container, this second portion having an extreme part suited to being coupled with the container near a corresponding opening of the container, 
 there being a place in the proximity of a zone of such body where the first and second portion are connected and the movable filter element, integral with the support unit, is inside said cavity and subject to said pressure element. 
 
     
     
       8. The vent and exhaust device according to  claim 7 , wherein said first portion of the body has a greater transverse dimension than a transverse dimension of the second portion, said first portion having a rest part on which rests the filter element or the support unit to create a seal on said rest part and to prevent, in absence of overpressure of gas inside the container, such gas from circulating around said filter element and passing through the device. 
     
     
       9. The vent and exhaust device according to  claim 1 , wherein the container is a container of moving parts, electrical parts, chemical parts, or a vehicle battery. 
     
     
       10. The vent and exhaust device according to  claim 1 , there being provided means of protection of the filter element from overpressure coming from the inside of the container. 
     
     
       11. The vent and exhaust device according to  claim 1 , wherein the filter element comprises internal stiffening units comprising a layer of plastic material. 
     
     
       12. The vent and exhaust device according to  claim 1 , wherein the filter element comprises internal stiffening units comprising a layer of nylon. 
     
     
       13. The vent and exhaust device according to  claim 1 , wherein the support unit is fixed to the filter element by one selected from the group consisting of comolding, ultrasonic welding, and thermowelding. 
     
     
       14. The vent and exhaust device according to  claim 1 , wherein the filter element comprises one selected from the group consisting of a membrane, a sinterized material, a polyester, a metallic salt, and a nonwoven material. 
     
     
       15. The vent and exhaust device according to  claim 1 , wherein the filter element is hydrophobic. 
     
     
       16. The vent and exhaust device according to  claim 1 , wherein the filter element is hydrophilic. 
     
     
       17. The vent and exhaust device according to  claim 1 , wherein the ring-shaped support unit comprises an annular face, surrounding the central hole, the annular face having a flat zone upon which an extremity of the pressure element rests, and a raised edge defining an open void above the filter element. 
     
     
       18. A vent and exhaust device for a container within which an overpressure of gas can be created during use, said device comprising:
 a hollow body for being arranged on an opening of the container, the hollow body having an upper portion and a lower portion, the lower portion defining a passage for connecting to the inside of the container, 
 an internal cavity of the hollow body being closed, but the upper portion communicating with the outside of the hollow body and the passage for connecting to the inside of the container, the gas that forms in the container is passable from the passage into the upper portion to vent to the outside of the hollow body, 
 on the passage being placed a filter element permeable to such gas at a first pressure, 
 a support unit for holding the filter unit, the support unit having a ring shaped form defining a central opening wherein the filter is within the support unit and extends across the central opening to block the opening and provide a through passageway for passing through the filter the gas that forms in the container, 
 a spring placed in the internal cavity of the body for directly exerting on the support unit a downward force for pushing the support unit and the filter element in the position of interception or closure of the passage, 
 the spring allowing the opening of the passage for a venting of the gas when the pressure exceeds a predetermined second pressure which is higher than said first pressure, but bringing such filter element back in the interception position when the pressure of the gas in the container returns below said predetermined value, 
 wherein the filter element is integral with the support unit. 
 
     
     
       19. The vent and exhaust device according to  claim 1 , wherein the filter element comprises one selected from the group consisting of a membrane, a sinterized material, a polyester, a metallic salt, and a nonwoven material. 
     
     
       20. The vent and exhaust device according to  claim 18 , wherein the ring-shaped support unit comprises an annular face, surrounding the central hole, the annular face having a flat zone upon which an extremity of the pressure element rests, and a raised edge defining an open void above the filter element.